Continued from page 1
If DNS server is unable to resolve query, it in turns queries other DNS servers, using a process known as recursion. DNS servers make use of root hints to assist in locating DNS servers, which are able to provide required result. In this way, DNS queries are minimised and Internet is able to operate quickly and effectively.
A typical query may run as follows:
Client contacts Nameserver A looking for www.discountdomainsuk.com.
Nameserver A checks its cache, but can’t answer, so it queries a server authoritive for Internet root.
The root server responds with a referral to a server authoritive for .com domains. NameserverA queries the .com server and gets referred to server authoritive for www.discountdomainsuk.com.
Nameserver A queries this server and gets IP address for www.discountdomainsuk.com.
Nameserver A replies to client with IP address.
Queries can return answers that are authoritive, positive, negative or referral in nature. In event of a negative answer, another DNS server is queried.
Clare Lawrence is CEO of Discount Domains Ltd – A leading UK provider of Domain name registration and Web Hosting services. Please feel free to re-publish this article provided this reference box remains together with a hyperlink to http://www.discountdomainsuk.com Clare can also be contacted on Clare@discountdomainsuk.com.